Goods are packed in wooden cases, with foam inside for protection. And we have a team who is in charge of packing. The team consists of our skilful carpenters and experienced packing designers. These enable our packing reasonable, safe and reliable.
SF6 gas insulated Combined transformers
The combined transformers combinate the characters of inductive voltage transformer and inductive current transformer, and it also has the function of current transformer and voltage transformer. The insulation material is SF6 gas.The bushing of the instrument transformer is made by silicon rubber or porcelain
The combined instrument transformer shall be suitable for measurement control and relay protection in the outdoor AC power system of nominal voltage 72.5~550kV, and frequency of 50 or 60Hz.
a. Ambient air temperature: maximum 40℃, minimum -40℃, average value of the ambient air temperature does not exceed 30℃ measured during a period of 24h.
b. Altitude: The altitude does not exceed 1000m (this is the routine requirement, if there is any different requirement, we can provide the products with 2000m, 3000m, 4000m or 5000m altitude according to the clients’ requirements)
c. The average value of the relative humidity does not exceed 95% at 25℃ measured during a period of one month
d. The maximum wind speed does not exceed 34m/s
e. Earthquake intensity does not exceed 8 degree
f. There have to be no gas that may seriously affect the insulation and conductive ability of electric equipments, steam, ash, salt, chemical deposit, pollution and corrosive or explosive material.
Main Technical Parameters
Rate voltage( kV)
power-frequency withstand voltage (r.m.s) (kV)
Rated lightning impulse withstand voltage (peak) (kV)
Rated switching impulse withstand voltage (peak) (kV)
Rated frequency( Hz)
Creepage distance mm/kV
25~31 or more
Ambient air temperature
-30/+50℃(special design is available of -60℃)
Current transformer part
Rated current( A)
100A ~ 4000A
Rated secondary current (A)
1A, 5A or others
0.2S,0.5S,5P,10P,PX,PR,TPX,TPY,TPZ or others
Voltage transformer part
Rated primary voltage (kV)
66/v√3,110/√3,132/√3,150/√3,220√3,330/√3,380√3 or 500/√3